# Global Agreement Reached to Abolish Leap Seconds by 2027 International authorities vote to replace leap seconds with a leap hour system. - **Source:** [New Scientist](https://www.newscientist.com/) - **Published:** 2026-10-16 - **Topic:** [Business](https://brifing.si/c/business) - **Original article:** - **On Brifing:** https://brifing.si/s/a3964706-237d-459a-8df2-46a8f45ee4af ## Global Timekeeping Shift Representatives from 69 countries voted on 15 October in Versailles to abolish leap seconds. This decision marks a significant departure from the practice of keeping clocks in sync with Earth's rotation. Starting 20 May 2027, the world will transition to a system allowing universal time to drift up to one hour. ## Atomic Clocks vs Rotation Since 1967, international time has relied on the vibration of caesium-133 atoms rather than the sun's position. Because Earth's rotation speed fluctuates, 27 leap seconds were added to Coordinated Universal Time since 1972. This manual correction process is now deemed incompatible with the requirements of modern, highly precise global digital infrastructure. ## Risks to Digital Systems Modern technological systems, including stock markets, telecommunications, and GPS, depend on continuous, uninterrupted timekeeping. Introducing leap seconds has historically triggered website crashes and disrupted airline booking systems. Experts like Setnam Shemar note that as time becomes more integrated into critical infrastructure, the complexity of these manual adjustments poses significant operational risks. ## The Negative Leap Threat Earth's rotation has recently accelerated, creating the unprecedented possibility of needing a negative leap second. Noël Dimarcq of the BIPM highlighted that the practical consequences of jumping backwards in time are difficult to predict. This potential instability accelerated the push to abandon the current system in favor of a more stable framework. ## The Leap Hour Solution The newly adopted leap hour strategy allows UTC to diverge from astronomical time for up to an hour before correction. This change ensures an uninterrupted flow of time for several centuries, according to Noël Dimarcq. It effectively removes the immediate pressure of frequent, small adjustments that previously threatened to destabilize complex global networks. ## Future Temporal Innovations Beyond the leap hour, the BIPM is exploring a new definition of the second. Current standards based on caesium clocks are being challenged by the superior accuracy of modern optical clocks. International agencies are also beginning to consider how to define a universal time standard specifically for lunar operations and future space exploration. ## Ongoing Astronomical Tracking Despite the abolition of leap seconds, physicists will continue to track Earth's rotation with high precision. This data remains essential for fields like astronomy and celestial navigation. The leap hour is expected to remain unnecessary for many hundreds or even thousands of years, maintaining the integrity of timekeeping for the foreseeable future. ## Impact on Global Infrastructure This transition represents a fundamental shift in how humanity manages time across digital platforms. By prioritizing the stability of telecommunications and electricity grids over astronomical alignment, the global community is adapting to a reality where technology dictates temporal precision. These changes will have a profound impact on future timekeeping on Earth and beyond. ## Sources covering this story - https://www.newscientist.com/article/2594285-scientists-have-just-voted-to-abolish-leap-seconds/?utm_campaign=RSS|NSNS&utm_content=home&utm_medium=RSS&utm_source=NSNS — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._